Syringe-supporting device for centrifuges

ABSTRACT

The syringe-supporting device for a centrifuge makes it possible to carry out centrifugation within the actual syringe which has been employed for sampling. The device comprises a pivotal cylindrical sleeve and two identical half-shells between which the syringe is clamped. Said half-shells are provided on the one hand with a groove for locking the cylinder of the syringe in position and on the other hand with a plurality of grooves for locking the plunger of the syringe in the position corresponding to the quantity of blood taken. Said half-shells are inserted in the sleeve in oppositely facing relation so that the pivotal motion of the latter should direct the plunger towards the exterior and the orifice of the syringe towards the axis of the centrifuge.

United States Patent Abbe et al.

[ Mar. 14, 1972 SYRINGE-SUPPORTING DEVICE FOR CENTRIFUGES [72] Inventors: Lucien Abbe, 83 rue Emile Duploye, 92, lssy-les-Moulineaux; Charles Sachs, 10 rue Erlanger, 75, both of Paris, France [22] Filed: Jan. 5, 1971 [21] Appl. No.: 103,995

[30] Foreign Application Priority Data Jan. 7, 1970 France ..7000354 [52] U.S. Cl ..233/26, 248/311 [51] Int. Cl ..B04b 9/00 [58] Field of Search ..248/311, 139; 233/26 [56] References Cited UNITED STATES PATENTS 3,339,837 9/1957 Harbott ..233/26 3,420,437 1/1969 Blum ..233/26 2,627,857 2/1953 Marcelli ..248/31l X FOREIGN PATENTS QR APPLICATIONS 894,010 9/ 1953 Germany ..233/26 Primary Examiner-Chancellor E. Harris Attorney-Cameron, Kerkam & Sutton [57] ABSTRACT The syringe-supporting device for a centrifuge makes it possible to carry out centrifugation within the actual syringe which has been employed for sampling.

The device comprises a pivotal cylindrical sleeve and two identical half-shells between which the syringe is clamped. Said half-shells are provided on the one hand with a groove for locking the cylinder of the syringe in position and on the other hand with a plurality of grooves for locking the plunger of the syringe in the position corresponding to the quantity of blood taken. Said half-shells are inserted in the sleeve in oppositely facing relation so that the pivotal motion of the latter should direct the plunger towards the exterior and the orifice of the syringe towards the axis of the centrifuge.

4 Claims, 4 Drawing Figures PATENTEDMARMIQR 7 3,648,927

SHEET 1 OF 2 g 1 'il ll J8 SYRlNGE-SUPPORTING DEVICE FOR CENTRIFUGES In a number of studies as biological blood tests, operations must essentially be performed without air from the time of sampling to the time of analysis. In point of fact, the most difficult stage of operation to be carried out in this manner is that of centrifugation for the purpose of separating red corpuscles of the blood from the plasma.

In some cases, the operation is carried out under a protective oil layer. The blood is taken into a syringe and then injected into a centrifuge bowl beneath an oil layer. The plasma is then collected by separation of the intermediate layer which is located between the oil and the red corpuscles of the blood.

In other cases, the blood-taking operation is carried out directly in a special vacuum tube and this tube is centrifuged without any transfer operation. In order to collect the plasma, it is then necessary either to unseal the tube or to carry out a fairly complex sampling operation with a double needle through a rubber stopper.

Both methods are costly by reason of the equipment which is necessary and they entail difficult handling operations without providing any absolute guarantee in regard to absence of air.

It has therefore been proposed to carry out the centrifugation within the actual syringe which has been employed for the blood-taking operation. However, a centrifuging operation of this kind calls for immediate locking of the plunger of the syringe as soon as the sampling has been completed in order to prevent any danger of penetration of air into said syringe and implies the need for a simple system for extracting the separated plasma.

The aim of this invention is to provide a device which makes it possible to solve these problems.

The invention is accordingly directed to a device for supporting a syringe on a centrifuge and comprising a cylindrical sleeve which is open at both ends, means for connecting said sleeve to the centrifuge in order to permit of pivotal motion of said sleeve about an axis at right angles to the axis of said sleeve, two identical half-shells which are inserted in said sleeve in order to retain between said half-shells the syringe employed for taking the blood to be centrifuged, each 'halfshell being provided with two portions having different diameters and at the junction of said two portions with a first internal groove for locking the cylinder of the syringe and at the extremity of the portion of smaller diameter with a number of internal grooves of which one groove locks the plunger of the syringe in the position corresponding to the quantity of blood taken.

As soon as the blood-taking operation has been completed, the syringe can thus be held in position between the two halfshells in order that the plunger should remain in contact with the sampled blood and prevent any penetration of air.

The shells which are inserted in the sleeve are capable of oscillating with respect to the centrifuge so that the syringe swings upwards to the horizontal position under the action of centrifugal force, the orifice of said syringe being directed towards the axis. In consequence, the red corpuscles accumulate against the plunger whilst the plasma is located in the vicinity of said orifice. Emptying of the syringe can thus be carried out simply by displacement of the plunger which discharges the plasma towards the exterior. No transfer or introduction of auxiliary components is necessary.

In accordance with an alternative embodiment which is adaptable to centrifuges of small diameter, the device comprises a counterweight of elongated shape and having an axis which is parallel to that of the sleeve, said counterweight being rigidly fixed to the sleeve and adapted to support the means for connecting said sleeve to the centrifuge.

A number of other advantages and characteristic features of the invention will also be brought out in the following description of one embodiment which is given by way of nonlimitative example and illustrated in the accompanying drawings, in which:

FIG. 1 is an axial sectional view of a supporting device in the position of rotation of the centrifuge;

FIG. 2 shows the means for connectingthe device to the centrifuge;

FIG. 3 is an axial sectional view of an alternative embodiment of the device which is also in the centrifugation position;

FIG. 4 is a sectional view taken along line I--I of FIG. 3.

The syringe-supporting device is essentially constituted by a cylindrical sleeve 1 which is open at both ends, two half-shells 2, 4 which surround the syringe 3 to be centrifuged being inserted in said sleeve. Each halfshell comprises two successive half-cylinders having different diameters. The large-diameter cylinder 2a, 4a fits exactly within the sleeve 1 and is provided at one end with a peripheral annular abutment flange 6 which is applied against said sleeve. The second cylinder 2b, 4b has a slightly larger diameter than that of the plunger of the syringe and preferably has an extension at the end remote from its junction with the cylinder 2a in the form of a cone frustum 5 in which are formed a number of internal annular grooves 8 for locking the extremity of said plunger 10.

The half-shells 2b and 4b are additionally provided with an annular groove 12 which is intended to engage over the end flange 13 of the syringe cylinder 14. On the other hand, said cylinder 14 passes freely through the end of each half-shell and extends beyond these latter and beyond the flange 6.

The sleeve 1 is in turn provided with two diametrically opposite external longitudinal slideways 18 which are each engaged over a stud 20 carried by one of the arms 22 of a forked member which forms the extremity of a radial arm 24 of said centrifuge.

On completion of the sampling or blood-taking operation, the two half-shells 2 and 4 are placed around the syringe 3, the groove 12 being intended to fit onto the flange 13 whilst one of the grooves 8 engages over the extremity of the plunger 10. Irrespective of the quantity of blood taken, the plurality of grooves 8 makes it possible for the plunger 10 to remain in contact with the blood sample. The plunger therefore closes the orifice of the syringe and prevents air from penetrating into this latter.

The assembly of half-shells and syringe is then inserted into the sleeve .1 until the abutment flange 6 rests on the top portion of the sleeve. The supporting device is then brought above the centrifuge whilst the syringe 3 remains vertical. The slideways 18 are engaged over the studs 20 and slide vertically on these latter until the ends of said slideways are applied against said studs 20.

Rotary motion of the centrifuge then causes pivotal motion of the sleeve 1 about the studs 20 from the vertical position to the horizontal position. The syringe is centrifuged in the position shown in FIG. 1 in which the plunger 10 is directed towards the exterior whilst the blood-sampling orifice is directed towards the axis of the centrifuge. During the rotary motion, the red corpuscles of the blood are therefore projected towards the plunger 10 and adhere to this latter. The plasma which is separated from said corpuscles remains located between these latter and the orifice of the syringe.

When centrifugation has been completed, the device returns automatically to the vertical position. The red corpuscles remain in contact with the plunger 10 and the plasma which is lighter remains at the top of the syringe. When said syringe has been withdrawn from the supporting device, it is then an easy matter to produce action on the plunger and to discharge the plasma alone into a suitable vessel.

Detachment of the syringe from the support as well as positioning of said syringe can be carried out without jerking of this latter and especially without any agitation. There is therefore no potential danger of accidental mixing of the red corpuscles with the plasma and the entire quantity of plasma can be collected. Said plasma has not been in contact with air at any moment and centrifugation has been carried out in a very simple manner without either transfer or introduction of any external component into the syringe.

In an alternative embodiment which is of special interest in the case of small-size centrifuges and which is illustrated in FIGS. 3 and 4, the sleeve 1 is rigidly fixed to a counterweight 16 of elongated shape whose axis is parallel to that of the syringe 3 and of the sleeve I. Said counterweight is provided on each lateral face with a longitudinal slideway 28 which is open at the free end of the counterweight but closed opposite to the sleeve 1. Said slideways provide a means for connecting the supporting assembly to the centrifuge. In fact, each slideway 28 cooperates with a stud 20 carried by one of the arms 22 of a forked member which forms the extremity of a radial arm 24 of said centrifuge.

As with the device of FIGS. 1 and 2, the syringe is mounted on the centrifuge in a vertical position, the slideways 28 slide over the studs 20 but the rotary motion of the centrifuge causes the counterweight 16 to swing upwards and places said syringe in the horizontal position, the sampling orifice being continuously directed towards the axis of the centrifuge. The assembly automatically returns to the vertical position as soon as the rotary motion stops; the red corpuscles remain in contact with the plunger and the plasma remains at the top of the syringe.

It is readily apparent that said device is not limited to centrifugation of blood but could also serve for other solutions which are intended to be strictly isolated from the surrounding air and are collected in a syringe.

A number of modifications could in any case be made in the embodiment which has just been described without thereby departing from the scope or the spirit of the invention. For example, the half-shells can be solid and conform substantially to the shape of the syringe or can alternatively be hollow and come into contact with said syringe only at their extremities and around the annular flanges. Similarly, the small-diameter cylinder or the cone frustum which may form an extension of this latter can be closed.

What we claim is:

l. A device for supporting a hypodermic syringe on a centrifuge and comprising a cylindrical sleeve which is open at both ends, means for connecting said sleeve to the centrifuge in order to permit of pivotal motion of said sleeve about an axis at right angles to the axis of said sleeve, two identical halfshells which are inserted in said sleeve in order to retain between said half-shells the syringe employed for sampling the blood to be centrifuged, each half-shell being provided with two portions having different diameters and at the junction of said two portions with a first internal groove for locking the cylinder of the syringe and at the extremity of the portion of smaller diameter with a number of internal grooves of which one groove locks the plunger of the syringe in the position corresponding to the quantity of blood taken.

2. A supporting device as defined in claim 1, wherein the larger-diameter portion of each half-shell is provided with a semi-annular peripheral abutment flange which bears on the sleeve.

3. A device as defined in claim 1, wherein said device comprises a counterweight of elongated shape and having an axis which is parallel to that of the sleeve, said counterweight being rigidly fixed to the sleeve and adapted to support the means for connecting said sleeve to the centrifuge.

4. A syringe-supporting device as defined in claim 3, wherein the counterweight has at least one longitudinal slideway in cooperating relation with a stud which is carried by the centrifuge. 

1. A device for supporting a hypodermic syringe on a centrifuge and comprising a cylindrical sleeve which is open at both ends, means for connecting said sleeve to the centrifuge in order to permit of pivotal motion of said sleeve about an axis at right angles to the axis of said sleeve, two identical half-shells which are inserted in said sleevE in order to retain between said half-shells the syringe employed for sampling the blood to be centrifuged, each half-shell being provided with two portions having different diameters and at the junction of said two portions with a first internal groove for locking the cylinder of the syringe and at the extremity of the portion of smaller diameter with a number of internal grooves of which one groove locks the plunger of the syringe in the position corresponding to the quantity of blood taken.
 2. A supporting device as defined in claim 1, wherein the larger-diameter portion of each half-shell is provided with a semi-annular peripheral abutment flange which bears on the sleeve.
 2. A supporting device as defined in claim 1, wherein the larger-diameter portion of each half-shell is provided with a semi-annular peripheral abutment flange which bears on the sleeve.
 3. A device as defined in claim 1, wherein said device comprises a counterweight of elongated shape and having an axis which is parallel to that of the sleeve, said counterweight being rigidly fixed to the sleeve and adapted to support the means for connecting said sleeve to the centrifuge.
 3. A device as defined in claim 1, wherein said device comprises a counterweight of elongated shape and having an axis which is parallel to that of the sleeve, said counterweight being rigidly fixed to the sleeve and adapted to support the means for connecting said sleeve to the centrifuge.
 4. A syringe-supporting device as defined in claim 3, wherein the counterweight has at least one longitudinal slideway in cooperating relation with a stud which is carried by the centrifuge.
 4. A syringe-supporting device as defined in claim 3, wherein the counterweight has at least one longitudinal slideway in cooperating relation with a stud which is carried by the centrifuge. 